But im curious about whether i need to plug in both those cables just to get to the serial console?
I was able to get serial access using the jtag board. Switch set to uart, use the uart port and 4 wire jumper to connect to the plug, and mini usb connector to computer.
I used minicom, ttyUSB0, 115200 8N1, no flow control. You can watch it boot, and then login.
Edit: Here's a link to documentation that you were requesting.http://code.google.com/p/guruplug/downloads/detail?name=GuruPlug%20Server-Quick%20Start%20Guide-100507.pdf